/*
 * Copyright (C) 2011 The Android Open Source Project
 * Copyright (C) 2011 Jake Wharton
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.viewpagerindicator;

import com.app.notepad.R;

import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v4.view.ViewPager.OnPageChangeListener;
import android.text.TextUtils.TruncateAt;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.HorizontalScrollView;
import android.widget.LinearLayout;
import android.widget.TextView;
import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;

/**
 * This widget implements the dynamic action bar tab behavior that can change
 * across different configurations or circumstances.
 */
public class TabPageIndicator extends HorizontalScrollView implements
	PageIndicator {
    /** Title text used when no title is provided by the adapter. */
    private static final CharSequence EMPTY_TITLE = "";

    /**
     * Interface for a callback when the selected tab has been reselected.
     */
    public interface OnTabReselectedListener {
	/**
	 * Callback when the selected tab has been reselected.
	 * 
	 * @param position
	 *            Position of the current center item.
	 */
	void onTabReselected(int position);
    }

    private Runnable mTabSelector;

    private final OnClickListener mTabClickListener = new OnClickListener() {
	public void onClick(View view) {
	    TabView tabView = (TabView) view;
	    final int oldSelected = mViewPager.getCurrentItem();
	    final int newSelected = tabView.getIndex();
	    mViewPager.setCurrentItem(newSelected);
	    if (oldSelected == newSelected && mTabReselectedListener != null) {
		mTabReselectedListener.onTabReselected(newSelected);
	    }
	}
    };

    private final IcsLinearLayout mTabLayout;

    private ViewPager mViewPager;
    private ViewPager.OnPageChangeListener mListener;

    private int mMaxTabWidth;
    private int mSelectedTabIndex;

    private OnTabReselectedListener mTabReselectedListener;

    public TabPageIndicator(Context context) {
	this(context, null);
    }

    public TabPageIndicator(Context context, AttributeSet attrs) {
	super(context, attrs);
	setHorizontalScrollBarEnabled(false);

	mTabLayout = new IcsLinearLayout(context,
		R.attr.vpiTabPageIndicatorStyle);
	addView(mTabLayout, new ViewGroup.LayoutParams(WRAP_CONTENT,
		MATCH_PARENT));
    }

    public void setOnTabReselectedListener(OnTabReselectedListener listener) {
	mTabReselectedListener = listener;
    }

    @Override
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
	final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
	setFillViewport(lockedExpanded);

	final int childCount = mTabLayout.getChildCount();
	if (childCount > 1
		&& (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) {
	    // if (childCount > 2) {
	    // mMaxTabWidth = (int)(MeasureSpec.getSize(widthMeasureSpec) *
	    // 0.4f);
	    // } else {
	    // mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2;
	    // }
	    mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec);

	} else {
	    mMaxTabWidth = -1;
	}

	final int oldWidth = getMeasuredWidth();
	super.onMeasure(widthMeasureSpec, heightMeasureSpec);
	final int newWidth = getMeasuredWidth();

	if (lockedExpanded && oldWidth != newWidth) {
	    // Recenter the tab display if we're at a new (scrollable) size.
	    setCurrentItem(mSelectedTabIndex);
	}
    }

    private void animateToTab(final int position) {
	final View tabView = mTabLayout.getChildAt(position);
	if (mTabSelector != null) {
	    removeCallbacks(mTabSelector);
	}
	mTabSelector = new Runnable() {
	    public void run() {
		final int scrollPos = tabView.getLeft()
			- (getWidth() - tabView.getWidth()) / 2;
		smoothScrollTo(scrollPos, 0);
		mTabSelector = null;
	    }
	};
	post(mTabSelector);
    }

    @Override
    public void onAttachedToWindow() {
	super.onAttachedToWindow();
	if (mTabSelector != null) {
	    // Re-post the selector we saved
	    post(mTabSelector);
	}
    }

    @Override
    public void onDetachedFromWindow() {
	super.onDetachedFromWindow();
	if (mTabSelector != null) {
	    removeCallbacks(mTabSelector);
	}
    }

    private void addTab(int index, CharSequence text, int iconResId) {
	final TabView tabView = new TabView(getContext());
	tabView.mIndex = index;
	tabView.setFocusable(true);
	tabView.setOnClickListener(mTabClickListener);
	tabView.setText(text);

	if (iconResId != 0) {
	    tabView.setCompoundDrawablesWithIntrinsicBounds(iconResId, 0, 0, 0);
	}

	mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0,
		MATCH_PARENT, 1));
    }

    @Override
    public void onPageScrollStateChanged(int arg0) {
	if (mListener != null) {
	    mListener.onPageScrollStateChanged(arg0);
	}
    }

    @Override
    public void onPageScrolled(int arg0, float arg1, int arg2) {
	if (mListener != null) {
	    mListener.onPageScrolled(arg0, arg1, arg2);
	}
    }

    @Override
    public void onPageSelected(int arg0) {
	setCurrentItem(arg0);
	if (mListener != null) {
	    mListener.onPageSelected(arg0);
	}
    }

    @Override
    public void setViewPager(ViewPager view) {
	if (mViewPager == view) {
	    return;
	}
	if (mViewPager != null) {
	    mViewPager.setOnPageChangeListener(null);
	}
	final PagerAdapter adapter = view.getAdapter();
	if (adapter == null) {
	    throw new IllegalStateException(
		    "ViewPager does not have adapter instance.");
	}
	mViewPager = view;
	view.setOnPageChangeListener(this);
	notifyDataSetChanged();
    }

    public void notifyDataSetChanged() {
	mTabLayout.removeAllViews();
	PagerAdapter adapter = mViewPager.getAdapter();
	IconPagerAdapter iconAdapter = null;
	if (adapter instanceof IconPagerAdapter) {
	    iconAdapter = (IconPagerAdapter) adapter;
	}
	final int count = adapter.getCount();
	for (int i = 0; i < count; i++) {
	    CharSequence title = adapter.getPageTitle(i);
	    if (title == null) {
		title = EMPTY_TITLE;
	    }
	    int iconResId = 0;
	    if (iconAdapter != null) {
		iconResId = iconAdapter.getIconResId(i);
	    }
	    addTab(i, title, iconResId);
	}
	if (mSelectedTabIndex > count) {
	    mSelectedTabIndex = count - 1;
	}
	setCurrentItem(mSelectedTabIndex);
	requestLayout();
    }

    @Override
    public void setViewPager(ViewPager view, int initialPosition) {
	setViewPager(view);
	setCurrentItem(initialPosition);
    }

    @Override
    public void setCurrentItem(int item) {
	if (mViewPager == null) {
	    throw new IllegalStateException("ViewPager has not been bound.");
	}
	mSelectedTabIndex = item;
	mViewPager.setCurrentItem(item);

	final int tabCount = mTabLayout.getChildCount();
	for (int i = 0; i < tabCount; i++) {
	    final View child = mTabLayout.getChildAt(i);
	    final boolean isSelected = (i == item);
	    child.setSelected(isSelected);

	    if (child instanceof TabView) {
		((TabView) child).setTextColor(isSelected ? this.getResources()
			.getColor(R.color.actionbar_color) : this
			.getResources().getColor(R.color.indicator_text_color));
	    }

	    if (isSelected) {

		animateToTab(item);
	    }
	}
    }

    @Override
    public void setOnPageChangeListener(OnPageChangeListener listener) {
	mListener = listener;
    }

    private class TabView extends TextView {
	private int mIndex;

	public TabView(Context context) {
	    super(context, null, R.attr.vpiTabPageIndicatorStyle);

	    this.setEllipsize(TruncateAt.MARQUEE);

	}

	@Override
	public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	    super.onMeasure(widthMeasureSpec, heightMeasureSpec);

	    // Re-measure if we went beyond our maximum size.
	    if (mMaxTabWidth > 0 && getMeasuredWidth() > mMaxTabWidth) {
		super.onMeasure(MeasureSpec.makeMeasureSpec(mMaxTabWidth,
			MeasureSpec.EXACTLY), heightMeasureSpec);
	    }
	}

	public int getIndex() {
	    return mIndex;
	}
    }
}
